Valve arrangement, in particular electromagnetic valve arrangement for slip-controlled motor vehicle brake systems

ABSTRACT

The present invention relates to a valve arrangement which includes a hydraulically actuatable non-return valve (1) and another, preferably electrically actuatable valve closure member (7), which are both positioned in a valve-accommodating bore (8) of the valve housing (12) in which the valve arrangement is received, wherein both valve closure members (17) cooperate with a valve seat member (4) in the valve housing (12). The non-return valve (1) is configured as a plate-type non-return valve with a flow opening (2) which is aligned coaxially to a first opening (3) of the valve seat member (4). Relative to the first opening (3) at least one bypass opening (5) is provided in the valve seat member (4) which is either closed or opened by a sealing surface (6) located to the side of the flow opening (2) of the non-return valve (1). A compact non-return valve (1) which is especially simple to make is thereby achieved.

TECHNICAL FIELD

The present invention relates to brake systems and more particularlyrelates to an electromagnetic valve arrangement for slip-controlledautomotive vehicle brake systems.

BACKGROUND OF THE INVENTION

German patent application No. 42 30 393 discloses a valve arrangement ofthe same type which establishes a direct pressure fluid connection (byway of a parallel connection of a spherical non-return valve to anotherelectromagnetically actuatable valve closure member) between a pressurefluid channel connected to a pressure fluid user and another pressurefluid channel connected to the pressure fluid source as soon as thehydraulic opening pressure of the non-return valve exceeds the closingpressure. The spherical non-return valve causes undesirably greatstructural efforts. Disadvantages are not only due to the overall heightof the valve arrangement but also to actions necessary for fixing andsealing the spherical non-return valve.

An object of the present invention is to provide a compact valvearrangement which permits an easy manufacture and assembly and ensuresreliability in operation without restrictions.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is a cross-sectional view of the valve arrangement of the presentinvention.

FIG. 2 is a top view of the non-return valve shown in FIG. 1.

FIG. 3 is an alternative embodiment for arranging a non-return valve inthe valve-accommodating member.

FIG. 4 is an alternative embodiment of the value seat member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a considerably enlarged sectional view of a valvearrangement, comprised of a rotationally symmetrical valve housing 12having a valve-accommodating bore 8 in which a disc-shaped valve seatmember 4 and a disc-shaped non-return valve 1 are fastened. Theattachment of both parts may preferably be performed by way of calkingof the valve housing 12. In the present embodiment, calking of thehousing material causes the valve seat member 4 to press the non-returnvalve 1 against a step of the valve-accommodating bore 8. FIG. 1 showsthe closed position of the non-return valve 1 in which the sealingsurface 6 facing the valve seat member 4 closes the bypass openings 5 inthe valve seat member 4 with its full surface. Exclusively the centrallydisposed flow opening 2 in the non-return valve 1 overlaps the opening 3of the valve seat member 4 which is positioned between the bypassopenings 5 in order to establish an unimpeded pressure fluid connectionbetween the pressure chambers placed upstream and downstream of thevalve seat member 4 in the open position of the valve closure member 7.The valve closure member 7 is arranged on the valve seat member 4 on theside remote from the non-return valve 1 and, when energizedelectromagnetically, closes the opening 3 which is bypassed in thepresence of a corresponding hydraulic pressure difference on thenon-return valve 1 by the sealing surface 6 lifting from the bypassopenings 5. A pressure fluid connection between the pressure chamberspositioned upstream and downstream of the valve seat member 4 is thenpermitted by way of the central flow opening 2 and alongside the slot 11in the non-return valve 1.

With reference to FIG. 1, the embodiment of FIG. 2 shows exclusively thenon-return valve 1 according to the present invention in a top view sothat the slot 11, which can initially be seen only as a bore in thenon-return valve 1 in FIG. 1, is now clearly visible as an opening whichextends in the shape of a circle segment. This circle-segment-shapedslot 11 delimits the central portion which forms the actual disc-shapedsealing surface 6 and includes the flow opening 2 as a central opening.Extending at the end of the slot 11 is an elastic web-shaped portion 10which connects the central portion to a fastening ring 9. Thus, thenon-return valve 1 has a first external portion which acts as fasteningring 9 and is connected to the central portion with sealing surface 6 byway of the elastic second web-shaped portion 10. The central portionacts quasi as a resilient tongue, by way of the elastic web-shapedportion 10, in order to lift from the end surface of the valve seatmember 4 caused by a hydraulic force applied to it, in conformity withrequirements.

With respect to this function, the recess in the valve-accommodatingbore 8 downstream of the non-return valve 1 shown in FIG. 1 isfurthermore referred to. The diameter of the recess is conformed to thediameter of the central portion limited by slot 11. Adjacent to thisdiameter is the step of the valve-accommodating bore 8 on which thefirst external portion abuts which acts as fastening ring 9. Thenon-return valve 1, illustrated as plate-type non-return valve, ispreferably made of spring steel or any comparable heat-treated sheetmetal. However, it is also possible to use other alternative materialswith corresponding elastic qualities.

FIG. 3 shows an alternative arrangement and embodiment of the non-returnvalve 1 which has generally a disc-shaped sealing surface 6 which, withits entire surface, is axially movable in the valve housing 12 betweenthe valve seat member 4 and the end portion of the valve-accommodatingbore 8. To ensure the free movability of the non-return valve 1 in thevalve-accommodating bore 8, said's disc diameter is chosen to becorrespondingly smaller than the diameter of the valve-accommodatingbore 8. Depending on the respective installation position of the valvearrangement, in the inactive operating position, the non-return valve 1under the effect of the force of gravity either bears against theannular end portion 13 of the valve-accommodating bore 4 as shown in thedrawing, or against the valve seat member 4, with the valve arrangementsuspended. Because this non-return valve 1 equally originates from FIGS.1 and 2, and the flow opening 2 and the opening 3 in the valve seatmember 4 are in conformity with each other, there is an unimpededpressure fluid connection between the pressure chambers on either sideof the valve seat member 4 when the valve closure member 7 is open.Opening 3 is closed when the valve closure member 7 iselectromagnetically energized so that a pressure fluid connectionbetween the pressure chambers disposed on either side of the valve seatmember 4 is permitted by way of the bypass openings 5 and the flowopening 2 in the non-return valve 1 at most due to a hydraulic pressuredifference acting on the non-return valve 1.

FIG. 4 shows an embodiment of the present invention which is stillimproved in comparison with FIG. 3.

The plate-shaped non-return valve 1 has the structural shape known fromFIG. 3. The valve seat member 4 is also identical to the constructionshown in FIG. 3. It should be noted that the non-return valve 1 can bemanufactured in a faced and surface-ground finishing operation insteadof from an etched rust-proof and surface-ground spring steel. The valveseat member 4 includes a step 14 to facilitate the assembly. Radialgrooves 15 in the bottom of the valve housing 12 are directed to thepressure fluid channel and assist the closing speed of the non-returnvalve 1 especially at cold temperatures. The present construction of thenon-return valve 1 is especially appropriate for incorporating adiaphragm function by etching an accurate small hole into the platestructure, which is absolutely unproblematic.

Those details shown in FIG. 4 which have not been referred to can betaken from the embodiments described hereinabove.

Concluding, the present invention is based on the fact that thenon-return valve 1 is configured as a plate-type non-return valve with aflow opening 2 which is aligned coaxially to a first opening 3 in thevalve seat member 4. At least one bypass opening 5 is arranged relativeto the first opening 3 in the valve seat member 4 and is either closedor opened by a sealing surface 6 that is arranged to the side of theflow opening 2 of the non-return valve 1. In terms of function, thenon-return valve 1 is arranged on the end surface of the valve seatmember 4 remote from the electromagnetically operable valve closuremember 7. Valve 1 with its sealing surface 6 is axially movable at leastin sections between the valve seat member 4 and a step of thevalve-accommodating bore 8.

What is claimed is:
 1. Valve arrangement, comprising:a valve housing; ahydraulically actuatable non-return valve; an electrically actuatablevalve closure member, wherein said hydraulically actuatable non-returnvalve and said electrically actuatable valve closure member are bothpositioned in a valve-accommodating bore of the valve housing, whereinsaid hydraulically actuatable non-return valve and said electricallyactuatable valve closure member both cooperate with a valve seat memberin the valve housing, wherein the non-return valve is configured as aplate-type non-return valve with a flow opening which is alignedcoaxially to a first opening of the valve seat member, in that relativeto the first opening in the valve seat member at least one bypassopening is provided which is either closed or opened by a sealingsurface located to the side of the flow opening of the non-return valve.2. Valve arrangement as claimed in claim 1, wherein the non-return valveis arranged on the end surface of the valve seat member which is remotefrom the valve closure member.
 3. Valve arrangement as claimed in claim2, wherein the non-return valve with its sealing surface is arrangedbetween the valve seat member and a step of the valve-accommodating boreso as to be axially movable at least in sections.
 4. Valve arrangementas claimed in claim 3, wherein the non-return valve has a first portionwhich acts as a fastening ring and is connected to a central portionincluding the sealing surface by way of an elastic and web-shaped secondportion.
 5. Valve arrangement as claimed in claim 4, wherein the centralportion is separated from the fastening ring by a slot which extends ina circular segment.
 6. Valve arrangement as claimed in claim 5, whereinthe elastic and web-shaped second portion connects the central portionto the fastening ring between the ends of the slot.
 7. Valve arrangementas claimed in claim 6, wherein the sealing surface includes a centralportion which includes a flow opening in its center.